Process for preparing phthalocyanine compounds

ABSTRACT

A process for preparing a mixture of copper phthalocyanine dyes of Formula (1): CuPc(SO 3 M) x (SO 2 NH 2 ) y , wherein: CuPc is copper phthalocyanine; M is a cation; x and y each independently have a value of from 0.5 to 3.5; and (x+y)=2 to 5; which process includes: chlorosulphonating a copper phthalocyanine compound using a chlorosulphonating agent; and condensing the product of step (i) with ammonia to give a mixture of copper phthalocyanine dyes of Formula (1); optionally exchanging the cation M in the mixture of copper phthalocyanine dyes of Formula (1) resulting from step (ii) for an alternative cation M; wherein the chlorosulphonating agent includes a mixture of chlorosulphonic acid and a chlorinating agent selected from phosphorous oxychloride and phosphorous trichloride. Also the dyes obtainable from this process; compositions and inks including these dyes; materials printed with these dyes, compositions or inks; ink-jet printer cartridges containing inks made from the dyes; and ink-jet printers including these cartridges.

This invention relates to a process for making mixtures of copperphthalocyanine dyes, to the resultant dye mixtures and to their use inink-jet printing.

Ink-jet printing (IJP) is a non-impact printing technique in whichdroplets of ink are ejected through a fine nozzle onto a substratewithout bringing the nozzle into contact with the substrate. The set ofinks used in this technique typically comprise yellow, magenta, cyan andblack inks.

With the advent of high-resolution digital cameras and ink-jet printersit is becoming increasingly common to print off photographs using anink-jet printer. This avoids the expense of conventional silver halidephotography and provides a print quickly without the need to post a filmto a developing service and wait days or weeks for it to be developedand returned.

While ink-jet printers have many advantages over other forms of printingand image development there are still technical challenges to beaddressed. For example, there are the contradictory requirements ofproviding ink colorants which are soluble in the ink medium and yet donot run or smudge excessively when printed on paper. The inks need todry quickly to avoid sheets sticking together after they have beenprinted, but they should not form a crust over the tiny nozzle used inthe printer. Storage stability is important to avoid particle formationthat could block the tiny nozzles used in the printer. Furthermore, theresultant images desirably do not fade rapidly on exposure to light orcommon oxidising gases such as ozone.

For a number of years C.I. Direct Blue 199 has been used as a colorantfor cyan inks used in ink-jet printing. While this colorant has manyproperties rendering it suitable for use in ink-jet printing, there is aneed for a colorant having superior resistance to fading and shadechange when exposed to oxidising gases such as ozone. The problems offading and shade change on contact with ozone is particularly acute whencyan colorants have been printed onto media containing inorganicparticles, e.g. silica and/or aluminina. There appears to be some aspectof the environment on the surface of such media (particularly media usedfor photorealistic ink-jet printing) which promotes deterioration ofthis dye in the presence of ozone.

A solution to the above problems is needed which also satisfies thecommercial need to manufacturing colorants at affordable prices. Inparticular, the manufacturing process should not involve too many stepsor be wasteful of starting materials or end product. It is alsoimportant that the manufacturing process is as convenient as possibleand that difficulties such as foaming are avoided wherever possible.

We have now found that use of a particular chlorosulphonating agent toprepare copper phthalocyanine dyes carrying sulphonic acid andsulphonamide (SO₂NH₂) groups results in dyes having useful propertiesfor ink-jet printing and, in particular, superior ozone fastness andshade stability compared to the dyes made by other processes.Furthermore these beneficial properties may be achieved in a highly costeffective manner.

According to the present invention there is provided a process forpreparing a mixture of copper phthalocyanine dyes of Formula (1):CuPc(SO₃M)_(x)(SO₂NH₂)_(y)  Formula (1)wherein:

-   -   CuPc is copper phthalocyanine;    -   M is a cation;    -   x and y each independently have a value of from 0.5 to 3.5; and    -   (x+y)=2 to 5;        which process comprises:    -   (i) chlorosulphonating a copper phthalocyanine compound using a        chlorosulphonating agent;    -   (ii) condensing the product of step (i) with ammonia to give a        mixture of copper phthalocyanine dyes of Formula (1); and    -   (iii) optionally exchanging the cation M in the mixture of        copper phthalocyanine dyes of Formula (1) resulting from        step (ii) for an alternative cation M;        wherein the chlorosulphonating agent comprises a mixture of        chlorosulphonic acid and a chlorinating agent selected from        phosphorous oxychloride and phosphorous trichloride.

The chlorosulphonation is optionally performed in a sequential mannerwhereby the copper phthalocyanine compound is first reacted with anexcess of chlorosulphonic acid and later a chlorinating agent is addedto the mixture of copper phthalocyanine compound and chlorosulphonicacid to form the chlorosulphonating agent in situ. However it ispreferred that the chlorosulphonation is performed in one step wherebythe copper phthalocyanine compound is in contact with thechlorosulphonating agent comprising both chlorosulphonic acid andchlorinating agent throughout the entire chlorosulphonation step. Thisone step process is simpler and less prone to errors than operating in asequential manner.

Preferably the chlorosulphonating agent comprises a mixture ofchlorosulphonic acid and phosphorous oxychloride.

The preferred molar ratio of chlorosulphonic acid to chlorinating agentused in the chlorosulphonating agent depends to some extent on the ratioof chlorosulphonic acid to copper phthalocyanine compound. In general,as the ratio of chlorosulphonic acid to copper phthalocyanine compoundincreases the optimum ratio of chlorosulphonic acid to chlorinatingagent in the chlorosulphonating agent also increases (i.e. lesschlorinating agent is needed when more chlorosulphonic acid is used.Bearing the above factors in mind, when the molar ratio ofchlorosulphonic acid to copper phthalocyanine compound is in the range10 to 75:1 then the molar ratio of chlorinating agent to copperphthalocyanine compound is preferably in the range 10 to 0.5:1. Morepreferably, when the molar ratio of chlorosulphonic acid to copperphthalocyanine compound is in the range 15 to 23:1 then the molar ratioof chlorinating agent to copper phthalocyanine compound is preferably inthe range 5 to 1:1.

In absolute terms, the molar ratio of chlorosulphonic acid to copperphthalocyanine compound is preferably in the range 5:1 to 200:1, morepreferably in the range 10:1 to 75:1 and especially in the range 15:1 to75:1.

The molar ratio of chlorinating agent to copper phthalocyanine ispreferably in the range 0.5:1 to 10:1, more preferably in the range0.75:1 to 7.5:1 and especially in the range 1:1 to 5:1.

Preferably chlorosulphonation is performed at a temperature in the rangeof from 90 to 180° C., more preferably 120 to 150° C., especially 130 to148° C. and more especially 135 to 145° C.

Preferably the chlorosulphonation is performed for 0.5 to 16 hours, morepreferably 1 to 8 hours, especially 1.5 to 5.0 hours. In a particularlypreferred embodiment chlorosulphonation is performed for 2 to 4 hours.

The length of time for which the chlorosulphonation is performed dependson the temperature used. For example higher temperatures require lesstime and lower temperatures require more time. In a preferred embodimentchlorosulphonation is performed at a temperature of 135 to 145° C. for atime of 1.5 to 5.0 (more preferably 2 to 4) hours.

The cholorosulphonating agent optionally comprises further ingredients,for example sulphuric acid. When sulphuric acid is present the molarratio of sulphuric acid to copper phthalocyanine compound is preferablyin the range 0.3:1 to 2:1, more preferably 0.6:1 to 1.2:1. Condensationof the product of step (i) with ammonia is preferably performed usingammonia in aqueous solution, e.g. ammonium hydroxide of strength 3 to 35weight %, preferably 7 to 13 weight %.

The amount of ammonia used in step (ii) will depend to some extent onthe composition of and amount of chlorosulphonating agent used in step(i). If a great excess of chlorosulphonating agent was used in step (i)then more ammonia is needed to neutralise excess acid before the processof reacting with —SO₂Cl groups on the phthalocyanine compound can begin.Thus the amount of ammonia used in step (ii) is preferably sufficient tobring the pH of the product of step (i) to a pH of 7 to 11, morepreferably a pH of 8 to 10.

Preferably condensation of the product of step (i) with ammonia isperformed at a temperature of 0 to 50° C., more preferably 10 to 45° C.and especially 12 to 40° C.

The length of time for which the condensation of the product of step (i)with ammonia is performed depends on the temperature used. For examplehigher temperatures require less time and lower temperatures requiremore time. In a preferred embodiment condensation of the product of step(i) with ammonia is performed at a temperature of 0 to 45° C. for a timeof 0.5 to 24 hours.

-   -   Preferably (x+y) has a value of 3 to 4.5, more preferably 3.5 to        4.4.    -   Preferably x has a value of 0.1 to 3, more preferably 0.2 to        2.2.    -   Preferably y has a value of 1 to 4, more preferably 1.8 to 3.5.    -   Preferably y has a value greater than or equal to x, more        preferably y has a value greater than x.

Preferably the values of x and y are such that when the compound ofFormula (1) has a solubility in water at 20° C. and pH 9 less than 25weight %, more preferably less than 20 weight % as measured using a 0.2micron filter. The solubility may be measured using the method describedin Example 13.

The cation represented by M is preferably an alkali metal salt,especially lithium, sodium and potassium, ammonium or a substitutedammonium salt (including a quaternary ammonium salt such as ((CH₃)₄N⁺)or a mixture thereof. Especially preferred are salts with sodium,lithium, ammonia and volatile amines, more especially sodium salts.

By following steps (i) and (ii) of the process according to the presentinvention a mixture of copper phthalocyanine dyes of Formula (1) willusually result where M is largely ammonium cations. However, if desiredthe product of step (ii) may be converted from the salt form arisingfrom step (ii) to the free acid form or an alternative salt form. Thusthe process optionally comprises step (iii) in which the cation Mresulting from step (ii) is exchanged for an alternative cation.

Any of the known techniques for exchanging one cation for another may beused to exchange cation M resulting from step (ii) for an alternativecation M. For example, the product of step (ii) may be acidified (e.g.using hydrochloric acid to give M=H), optionally followed by dialysis,to remove the original cations with subsequent addition of alternativecations M (e.g. by addition of alkali metal hydroxide, ammonium salt oramine). Use of ion exchange resins and reverse osmosis are amongst theother well-known techniques for exchanging one cation for another.

Preferably the mixture of copper phthalocyanine dyes obtained by theprocess is such that when the mixture has been printed onto microporouspaper (e.g. Epson Premium Photopaper and Canon PR101 Photopaper) itloses less than 20% of its optical density, more preferably less than15% of its optical density, especially less than 10% of its opticaldensity, more especially less than 7% of its optical density andparticularly less than 5% of its optical density when exposed to 1 partper million of ozone for 24 hours at 40° C. and 50% humidity.

Taking account of the preferences described above, a particularlypreferred embodiment of the process is where:

-   -   x has a value of 0.2 to 2.2;    -   y has a value of 1.8 to 3.5;    -   y has a value greater than or equal to x; and    -   (x+y)=3.5 to 4.4;        and the process comprises:    -   (i) chlorosulphonating a copper phthalocyanine compound at a        temperature of 135 to 145° C. for a period of 1.5 to 5.0 hours        using a chlorosulphonating agent; and    -   (ii) condensing the product of step (i) at a temperature in the        range 10 to 45° C. for 0.5 to 24 hours with ammonia in the form        of ammonium hydroxide at a pH in the range 8 to 10 to give a        mixture of copper phthalocyanine dyes of Formula (1);    -   (iii) optionally exchanging the cation M in the mixture of        copper phthalocyanine dyes of Formula (1) resulting from        step (ii) for an alternative cation M; and        wherein the chlorosulphonating agent comprises a mixture of        chlorosulphonic acid and a chlorinating agent selected from        phosphorous oxychloride and phosphorous trichloride, preferably        phosphorous oxychloride, such that the molar ratio of        chlorosulphonic acid to copper phthalocyanine compound is in the        range 15 to 23:1 and the molar ratio of said chlorinating agent        to copper phthalocyanine compound is in the range 5 to 1:1.

Preferably the process of the present invention is free from steps inwhich the absorbance of the phthalocyanine compound of Formula (1)between 640 and 670 nm is lowered relative to the absorbance at 590 to630 nm by removal of phthalocyanine compounds having an absorbance peakbetween 640 and 670 nm. For example, the process is preferably free fromprecipitation (e.g. salting-out) and filtration steps which removephthalocyanine compounds having an absorbance peak between 640 and 670nm more efficiently than phthalocyanine compounds lacking an absorbancebetween 640 and 670 nm. The reason for this preference is that removalof the phthalocyanine compounds having an absorbance peak between 640and 670 nm is wasteful since it is an extra process step and the removedcompounds are thrown away. The process of the present invention may beperformed such that there is no need to remove such phthalocyaninecompounds because they do not arise or they arise only to a much lowerextent than when chlorosulphonic acid is used without the specifiedchlorinating agents being present.

A second aspect of the invention provides a mixture of copperphthalocyanine dyes of Formula (1) as hereinbefore defined obtainable bya process according to the first aspect of the invention.

Mixtures of copper phthalocyanine dyes according to the second aspect ofthe invention have attractive, strong cyan shades and are valuablecolorants for use in the preparation of ink-jet printing inks. Theybenefit from a good balance of solubility, storage stability andfastness to water and light. In particular, compared to knownpreparations of Direct Blue 199, they display excellent light and ozonefastness. Furthermore they may be prepared using existing productionfacilities from cheap intermediates thus avoiding the complexity andexpense associated with the manufacture of more elaborate phthalocyaninedye structures.

According to a third aspect of the present invention there is provided acomposition comprising a mixture of copper phthalocyanine dyes accordingto the second aspect of the invention and a liquid medium.

Preferred compositions comprise:

-   -   (a) from 0.01 to 10 parts of a mixture of copper phthalocyanine        dyes according to the second aspect of the invention; and    -   (b) from 90 to 99.99 parts of a liquid medium;        wherein all parts are by weight and the number of parts of        (a)+(b)=100.

Preferred liquid media include water, a mixture of water and organicsolvent and organic solvent free from water.

When the medium comprises a mixture of water and organic solvent, theweight ratio of water to organic solvent is preferably from 99:1 to1:99, more preferably from 99:1 to 50:50 and especially from 95:5 to80:20.

It is preferred that the organic solvent present in the mixture of waterand organic solvent is a water-miscible organic solvent or a mixture ofsuch solvents. Preferred water-miscible organic solvents includeC₁₋₆-alkanols, preferably methanol, ethanol, n-propanol, isopropanol,n-butanol, sec-butanol, tert-butanol, n-pentanol, cyclopentanol andcyclohexanol; linear amides, preferably dimethylformamide ordimethylacetamide; ketones and ketone-alcohols, preferably acetone,methyl ether ketone, cyclohexanone and diacetone alcohol; water-miscibleethers, preferably tetrahydrofuran and dioxane; diols, preferably diolshaving from 2 to 12 carbon atoms, for example pentane-1,5-diol, ethyleneglycol, propylene glycol, butylene glycol, pentylene glycol, hexyleneglycol and thiodiglycol and oligo- and poly-alkyleneglycols, preferablydiethylene glycol, triethylene glycol, polyethylene glycol andpolypropylene glycol; triols, preferably glycerol and 1,2,6-hexanetriol;mono-C₁₋₄-alkyl ethers of diols, preferably mono-C₁₋₄-alkyl ethers ofdiols having 2 to 12 carbon atoms, especially 2-methoxyethanol,2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)-ethanol,2-[2-(2-methoxyethoxy)ethoxy]ethanol,2-[2-(2-ethoxyethoxy)-ethoxy]-ethanol and ethyleneglycol monoallylether;cyclic amides, preferably 2-pyrrolidone, N-methyl-2-pyrrolidone,N-ethyl-2-pyrrolidone, caprolactam and 1,3-dimethylimidazolidone; cyclicesters, preferably caprolactone; sulphoxides, preferably dimethylsulphoxide and sulpholane. Preferably the liquid medium comprises waterand 2 or more, especially from 2 to 8, water-miscible organic solvents.

Especially preferred water-miscible organic solvents are cyclic amides,especially 2-pyrrolidone, N-methyl-pyrrolidone and N-ethyl-pyrrolidone;diols, especially 1,5-pentane diol, ethyleneglycol, thiodiglycol,diethyleneglycol and triethyleneglycol; and mono- C₁₋₄-alkyl andC₁₋₄-alkyl ethers of diols, more preferably mono-C₁₋₄alkyl ethers ofdiols having 2 to 12 carbon atoms, especially2-methoxy-2-ethoxy-2-ethoxyethanol. When the liquid medium comprises amixture of water and organic solvent or an organic solvent free fromwater component (a) is preferably completely dissolved in component (b).The liquid media may of course contain additional componentsconventionally used in ink-jet printing inks, for example viscosity andsurface tension modifiers, corrosion inhibitors, biocides, kogationreducing additives and surfactants which may be ionic or non-ionic.

Although not usually necessary, further colorants may be added to theink to modify the shade and performance properties. Examples of suchcolorants include C.I. Direct Yellow 86, 132, 142 and 173; C.I. DirectBlue 307; C.I. Food Black 2; C.I. Direct Black 168 and 195; C.I. AcidYellow 23; and any of the dyes used in ink-jet printers sold by SeikoEpson Corporation, Hewlett Packard Company, Canon Inc. & LexmarkInternational.

It is preferred that the composition according to the second aspect ofthe invention is an ink suitable for use in an ink-jet printer.

The inks may be incorporated in an ink-jet printer as a highconcentration cyan ink, a low concentration cyan ink or both a highconcentration and a low concentration ink. In the latter case this canlead to improvements in the resolution and quality of printed images.Thus the present invention also provides a composition according to thethird aspect of the present invention (preferably an ink) wherecomponent (a) is present in an amount of 2.5 to 7 parts, more preferably2.5 to 5 parts (a high concentration ink) or component (a) is present inan amount of 0.5 to 2.4 parts, more preferably 0.5 to 1.5 parts (a lowconcentration ink).

Thus, preferably the ink has a viscosity of less than 20 cP, morepreferably less than 10 cP, especially less than 5 cP, at 25° C. Theselow viscosity inks are particularly well suited for application tosubstrates by means of ink-jet printers.

Preferably the ink contains less than 500 ppm, more preferably less than250 ppm, especially less than 100 ppm, more especially less than 10 ppmin total of divalent and trivalent metal ions (other than any divalentand trivalent metal ions bound to a component of the ink).

Preferably the ink has been filtered through a filter having a mean poresize below 10 μm, more preferably below 3 μm, especially below 2 μm,more especially below 1 μm. This filtration removes particulate matterthat could otherwise block the fine nozzles found in many ink-jetprinters.

Preferably the ink contains less than 500 ppm, more preferably less than250 ppm, especially less than 100 ppm, more especially less than 10 ppmin total of halide ions.

A fourth aspect of the invention provides a process for forming an imageon a substrate comprising applying an ink according to the third aspectof the invention thereto by means of an ink-jet printer.

The ink-jet printer preferably applies the ink to the substrate in theform of droplets that are ejected through a small orifice onto thesubstrate. Preferred ink-jet printers are piezoelectric ink-jet printersand thermal ink-jet printers. In thermal ink-jet printers, programmedpulses of heat are applied to the ink in a reservoir by means of aresistor adjacent to the orifice, thereby causing the ink to be ejectedfrom the orifice in the form of small droplets directed towards thesubstrate during relative movement between the substrate and theorifice. In piezoelectric ink-jet printers the oscillation of a smallcrystal causes ejection of the ink from the orifice. Alternately the inkcan be ejected by an electromechanical actuator connected to a moveablepaddle or plunger, for example as described in International PatentApplication WO00/48938 and International Patent Application WO00/55089.

The substrate is preferably paper, plastic, a textile, metal or glass,more preferably paper, an overhead projector slide or a textilematerial, especially paper.

Preferred papers are plain or treated papers which may have an acid,alkaline or neutral character. Glossy papers are especially preferred.

A fifth aspect of the present invention provides a material preferablypaper, plastic, a textile, metal or glass, more preferably paper, anoverhead projector slide or a textile material, especially paper moreespecially plain, coated or treated papers printed with a compositionaccording to the third aspect of the invention, a mixture of copperphthalocyanine dyes according to the second aspect of the invention orby means of a process according to fourth aspect of the invention.

A sixth aspect of the present invention provides an ink-jet printercartridge comprising a chamber and an ink wherein the ink is in thechamber and the ink is as defined in the third aspect of the presentinvention. Preferably the cartridge contains a high concentration inkand a low concentration ink as described above in different chambers.

A seventh aspect of the present invention provides an ink-jet printercomprising a cartridge as defined in the sixth aspect of the presentinvention The invention is further illustrated by the following Examplesin which all parts and percentages are by weight unless otherwisestated.

EXAMPLE 1

Step (i)—Chlorosulphonating a Copper Phthalocyanine Compound using aChlorosulphonating Agent Comprising a Mixture of Chlorosulphonic Acidand POCl₃.

Phosphorus oxychloride (4.7 ml, 7.7 g, 0.05 mole) was added tochlorosulphonic acid (61.6 ml, 109.0 g, 0.93 mole). Copperphthalocyanine (23.5 g, 0.04 mole) was then added in small portionswhile maintaining the temperature below 60° C. When the addition ofcopper phthalocyanine was complete the reaction mixture was heated to140° C. over the course of about 30 minutes. The reaction mixture wasmaintained at 140° C. for 3 hr and then cooled to ambient temperatureand stirred for 30 minutes. The reaction mixture was then added to amixture of ice/water (800 g) and salt (20 g) at ≦0° C. More ice wasadded to maintain the temperature below 0° C. The resultant copperphthalocyanine sulphonyl chloride product was filtered-off and washedwith ice cold 5% brine (250 ml). The resultant copper phthalocyaninesulphonyl chloride paste was then added to an ice/water mixture (300 g)and stirred until dispersed.

Step (ii)—Condensing the Product of Step (i) with Ammonia to give aMixture of Copper Phthalocyanine Dyes of Formula (1).

The pH of the dispersion resulting from step (i) was then raised to pH9.5 using 10% ammonia solution. The temperature of the mixture was thenallowed to rise slowly to room temperature while maintaining the pH at9.5±0.1 using 10% ammonia solution. The reaction mixture was thenstirred overnight at pH 9.5 and room temperature. Next morning themixture was stirred rapidly while the pH was adjusted to pH 6.5 usingconcentrated hydrochloric acid. Saturated brine (100 ml) was added andthe pH was reduced to pH 3.5 using concentrated hydrochloric acid. Theproduct was collected by filtration and the resultant paste was stirredin water (1000 ml) and rendered soluble by adjusting the pH to 9.5 bythe addition of 2M NaOH. The solution so formed was dialysed to removeinorganic salts then screened through GF/F paper. The filtrate was driedin an oven at 50° C. overnight to yield a mixture of copperphthalocyanine dyes of Formula (1) wherein M is sodium, x is 1.2 and yis 2.7 (34.3 g).

EXAMPLES 2 TO 11

The method of Example 1 was repeated except that the relative molaramounts of copper phthalocyanine (“CuPc”), chlorosulphonic acid (“CSA”),H₂SO₄ and chlorinating agent (POCl₃) were as shown in Table 1 below. The6^(th) and 7^(th) columns in Table 1 show respectively the length oftime and temperature at which the chlorosulphonation was performed. Thefinal two columns in Table 1 show the values of x and y in the resultantmixture of copper phthalocyanine dyes of Formula (1).

TABLE 1 Tem- per- Time ature CuPc CSA H₂SO₄ POCl₃ (hours) (° C.) x yExample 2 1 50 0 3.8 4 140 0.1 4.0 Example 3 1 23 0 1.5 4 140 — —Example 4 1 23 0 1 4 140 1.3 2.7 Example 5 1 23 0 1.35 3 140 1.8 1.8Example 6 1 23 0 1.25 3 140 1.6 2.1 Example 7 1 23 0.9 1.35 3 140 — —Example 8 1 23 0 0.88 3 140 1.6 2.5 Example 9 1 23 0 2.1 4 140 — —Example 10 1 23 0 1 3 120 — — Example 11 1 23 0 0.5 3 120 — — — meansnot measured.

COMPARATIVE EXAMPLE

The comparative mixture of copper phthalocyanine dyes was C.I. DirectBlue 199 obtained as Pro-Jet ™Cyan 1 from Avecia Limited.

EXAMPLE 12 Preparation of Inks

Inks 1 to 11 and Comparative Ink 1 were prepared by dissolving 0.7 g ofdye mixture from the above Examples 1 to 11 and Pro-Jet ™Cyan 1respectively in 19.3 g of a liquid medium comprising:

Thiodiglycol 5% Urea 2.5% 2-Pyrollidone 2.5% Surfynol ™ 465 1% Water 89%(all % by weight)and adjusting the pH of the ink to pH 8-10 using sodium hydroxide.Surfynol™ 465 is a surfactant from Air Products Ltd.

EXAMPLE 13 Ink-Jet Printing and Results

Solubility Measurements

Solubility of the dye mixtures resulting from Examples 1 to 11 weremeasured as follows:

A saturated slurry of the dye mixture under investigation, in water, wasplaced in a freeze thaw (−15 to +25° C.) cabinet for 3 days and thenallowed to reach room temperature over 2 hours. The pH was adjusted to9. A portion was then filtered through a 0.2 micron syringe filter. Afew drops of the filtrate (which represents a solution of the dyemixture having the maximum concentration of dye achievable) wereaccurately weighed and its absorbance at a given wavelength wasmeasured. This absorbance measurement was compared to a previouslyconstructed calibration curve showing absorbance versus concentrationand the concentration of dye mixture at read from the curve. Thisconcentration was the solubility of the dye at pH 9.

This experiment was then repeated filtering through a 0.02 micronsyringe filter.

The solubility results are shown in Table 2 below.

Ink-Jet Printing

Inks 1 to 11 and Comparative Ink 1, described in Example 12, werefiltered through 0.45 micron nylon filters and then incorporated intoempty EPSON 880 print cartridges using a syringe.

The inks were then printed using an EPSON 880 Printer, using the AdobeHalf Test print program, onto EPSON Premium Photopaper (“SEC PM”) andCanon PR101 Photopaper (“PR101”). The resultant prints at 100% were thentested for ozone fastness by exposure to 1 ppm ozone at 40° C., 50%relative humidity for 24 hrs in a Hampden 903 Ozone cabinet.

The Delta E and % OD loss were measured.

Results

TABLE 2 % Solubility % Solubility 0.2 micron 0.02 micron Delta E % ODLoss Delta E % OD Loss filter filter PR101 PR101 SEC PM SEC PM Ink 1 189.3 14 0 10  0 Ink 2 7.7 4.8  1 −1  1  3 Ink 3 14.7 — 20 0 14  2 Ink 422.9 15.7 35 13 19 16 Ink 5 19.9 — 37 12 23 18 Ink 6 22.7 14.6 16 2 14 0 Ink 7 19.7 19.68 — — — — Ink 8 19.7 12.1 33 13 21 16 Ink 9 13.8 — — —— — Comparative 35.75 33.93 52 43 27 24 Ink 1 — means not measured.Table 2 shows that the dye mixtures of the present invention have alower OD loss in ozone (i.e. higher ozone fastness) and a lower Delta Ein ozone (i.e. lower shade change) than conventional C.I Direct Blue199.

EXAMPLE 14

Further Inks

The inks described in Tables I to II may be prepared using the mixtureof copper phthalocyanine dyes made in Example 1. Numbers quoted in thesecond column onwards refer to the number of parts of the relevantingredient and all parts are by weight. The inks may be applied to paperby thermal or piezo ink-jet printing.

The following abbreviations are used in Table I and II:

-   -   PG=propylene glycol    -   DEG=diethylene glycol    -   NMP=N-methyl pyrollidone    -   DMK=dimethylketone    -   IPA=isopropanol    -   MEOH=methanol    -   2P=2-pyrollidone    -   MIBK=methylisobutyl ketone    -   P12=propane-1,2-diol    -   BDL=butane-2,3-diol    -   CET=cetyl ammonium bromide    -   PHO=Na₂HPO₄ and    -   TBT=tertiary butanol    -   TDG=thiodiglycol

TABLE I Dye Na Dye Content Water PG DEG NMP DMK NaOH Stearate IPA MEOH2P MIBK 1 2.0 80 5 6 4 5 2 3.0 90 5 5 0.2 3 1 85 3 3 3 5 1 4 2.1 91 8 15 3.1 86 5 0.2 4 5 6 1.1 81 9 0.5 0.5 9 7 2.5 60 4 15 3 3 6 10 5 4 8 565 20 10 9 2.4 75 5 4 5 6 5 10 4.1 80 3 5 2 10 0.3 11 3.2 65 5 4 6 5 4 65 5 5.1 96 4 1 1.8 90 5 5 2 1 80 2 6 2 5 1 4 3 1.8 80 5 15 4 2.6 84 11 55 3.3 80 2 10 2 6 6 7 90 7 0.3 3 7 5.4 69 2 20 2 1 3 3 8 6.0 91 4 5

TABLE II Dye Dye Content Water PG DEG NMP CET TBT TDG BDL PHO 2P PI2 93.0 80 15 0.2 5 10 4 90 5 1.2 5 11 1.5 85 5 5 0.15 5.0 0.2 1 2.5 90 6 40.12 2 3.1 82 4 8 0.3 6 3 0.9 85 10 5 0.2 4 4 90 5 5 0.3 5 4.0 70 10 4 14 11 6 2.2 75 4 10 3 2 6 10 4 91 6 3 7 3 76 9 7 3.0 0.95 5 8 5.0 78 5 116 9 5.4 86 7 7 10 2.1 70 5 5 5 0.1 0.2 0.1 5 0.1 5 11 2.0 90 10 1 2 8810 2 5 78 5 12 5 1 7 70 2 8 15 5 1 2.2 80 8 12 1 1.4 80 10

1. In a process for preparing a mixture of copper phthalocyanine dyes ofFormula (1):CuPc(SO₃M)_(x)(SO₂NH₂)_(y)  Formula (1) wherein: CuPc is copperphthalocyanine; M is a cation; x and y each independently have a valueof from 0.5 to 3.5; and (x+y)=2 to 5; which process comprises: (i)chlorosulphonating a copper phthalocyanine compound using achlorosulphonating agent; and (ii) condensing the product of step (i)with ammonia to give a mixture of copper phthalocyanine dyes of Formula(1); (iii) optionally exchanging the cation M in the mixture of copperphthalocyanine dyes of Formula (1) resulting from step (ii) for analternative cation M; the improvement wherein the chlorosulphonatingagent used in (i) comprises a mixture of chlorosulphonic acid andphosphorous oxychloride the molar ratio of chlorosulphonic acid tocopper phthalocyanine compound in (i) being in the range 10 to 75:1 andthe molar ratio of phosphorous oxychloride to copper phthalocyaninecompound being in the range 10 to 0.5:1.
 2. A process according to claim1 wherein the chlorosulphonation is performed in one step whereby saidcopper phthalocyanine compound is in contact with saidchlorosulphonating agent comprising both chlorosulphonic acid andphosphorous oxychloride throughout the entire chlorosulphonation step.3. A process according to claim 1 wherein y has a value greater than orequal to x.
 4. A process according to claim 1 wherein: x has a value of0.2 to 2.2; y has a value of 1.8 to 3.5; y has a value greater than orequal to x; and (x+y)=3.5 to 4.4; and the process comprises: (i)chlorosulphonating a copper phthalocyanine compound at a temperature of135 to 145° C. for a period of 2.5 to 5.5 hours using achlorosulphonating agent; and (ii) condensing the product of step (i) ata temperature in the range 10 to 45° C. for 0.5 to 24 hours with ammoniain the form of ammonium hydroxide at a pH in the range 8 to 10 to give amixture of copper phthalocyanine dyes of Formula (1); (iii) optionallyexchanging the cation M in the mixture of copper phthalocyanine dyes ofFormula (1) resulting from step (ii) for an alternative cation M; andwherein the chlorosulphonating agent comprises a mixture ofchlorosulphonic acid and phosphorous oxychloride such that the molarratio of chlorosulphonic acid to copper phthalocyanine compound is inthe range 15 to 23:1 and the molars ratio of said phosphorus oxychlorideto copper phthalocyanine compound is in the range 5 to 1:1.
 5. Themixture of copper phthalocyanine dyes obtained by the process accordingto claim
 1. 6. A composition comprising a mixture of copperphthalocyanine dyes according to claim 5 and a liquid medium.
 7. Acomposition according to claim 6 wherein the liquid medium comprises amixture of water and organic solvent.
 8. A composition according toclaim 6 which is an ink suitable for use in an ink-jet printer.
 9. Aprocess for forming an image on a substrate comprising applying theretoan ink according to claim 8 by means of an ink-jet printer.
 10. A paper,plastic, a textile, metal or glass, printed with a composition accordingto any one of claims 6 to
 8. 11. An ink-jet printer cartridge comprisinga chamber and an ink wherein the ink is in the chamber and the ink is asdefined in claim
 8. 12. An ink-jet printer cartridge comprising achamber and an ink wherein the ink is in the chamber and wherein saidcartridge contains a high concentration ink and a low concentration inkaccording to claim
 8. 13. An ink-jet printer comprising a cartridge asdefined in claim 11 or 12.